1. Field of the Invention
The present invention relates to systems including a strip material of the type having chambers formed between two heat sealable films and a device for filling and sealing the chambers of the strip material to form air cushioning material.
2. Description of the Prior Art
U.S. Pat Nos. 3,660,189 and 3,868,285 describe systems and devices for providing air cushioning material in which (1) an elongate strip material is prepared by fusing together two flexible heat sealable films in discrete areas to define a plurality of chambers between the films with each chamber having an inlet opening; (2) the strip material is shipped to the site of its intended use; and (3) a device is then used to inflate and seal the chambers to form air cushioning material. This type of system reduces bulk handling problems and the costs of shipping air which would otherwise result if the strip material were inflated and sealed at a central production facility and was then shipped in an inflated condition to the site of its intended use. The chambers formed prior to inflation in the systems of U.S. Pat. Nos. 3,660,189 and 3,868,285, however, extend transversely nearly across the strip material. Each chamber has at least one end which is open across the entire width of the chamber to provide the inlet opening and is positioned adjacent a longitudinal edge of the strip material. The strip material is moved to sequentially position the open ends of the chambers adjacent to a nozzle through which air flows to inflate the chambers, and the device must then perform extensive heat sealing operations both to seal across the open ends of the chambers, and to divide the chambers longitudinally of the strip material into smaller chambers of a more suitable size. Because of the large number of seals that must be made, the filling and sealing device is more complex and expensive than might be desired to afford the use of such a system by a small manufacturing facility. Also, sealing across the full width of the inflated chambers causes wrinkles which tend to leak air through the sealed areas. This occurs because opposed arcuate lengths of each film are gathered and sealed together in about the length of their common cord.